Tissue resection system

ABSTRACT

A surgical system can include a first instrument defining a first channel and a second instrument receivable by the first channel. The second instrument can include a second channel. A valve coupled to the first instrument controls fluid flow through the first channel. The valve has at least two positions and in one position, the impedance of fluid flow through the valve into the first channel (when the second instrument is not received in the first channel) is substantially the same as when the valve is the other position and the first channel partially blocked by the second instrument. In another aspect, a surgical system can include an outer member and the first instrument can be received within the outer member to define a second channel there between. The first instrument can include a visualization system and an illumination system.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation application of U.S. patentapplication Ser. No. 15/544,985, filed on Jul. 20, 2017, which is a U.S.National Stage Application under 35 U.S.C. § 371(a) of PCT/US2015/013356filed Jan. 28, 2015, the entire contents of each of which areincorporated by reference herein.

FIELD OF THE INVENTION

This present disclosure relates to a tissue resecting system.

BACKGROUND

Endoscopic surgery of a distensible organ, such as a uterus, may beperformed with an endoscope that is insertable into the uterus throughthe cervix and a resector or other tool that passes through theendoscope to cut or otherwise treat tissue in the uterus. Duringsurgery, it often is desirable to distend the uterus with a fluid, suchas saline, sorbitol, or glycine, in order provide a visible workingspace. Fluid can be infused into the uterus and removed from the uterusthrough the endoscope and/or the resector.

If the outflow of fluid from the uterus is greater than the inflow offluid to the uterus, the uterus may collapse back to its normal state,making visualization of the uterus difficult. On the other hand, if theinflow of fluid is greater than the outflow of fluid such that thepressure created by the fluid is greater than the patient's meanarterial pressure, excess fluid can enter the patient's vascular system(known as intravasation), which can lead to serious complications orinjury.

The proximal end of the endoscope can include an access port for theworking channel into which the resector can be inserted enabling thedistal cutting end of the resector to travel through the working channeland beyond the distal end of the endoscope in the uterus to cut orotherwise treat tissue in the uterus. The distention fluid also entersthe uterus through the working channel of the endoscope.

The endoscope can be used in two modes, diagnostic mode and operativemode. In diagnostic mode, the endoscope can be used to view inside theuterus in order to identify tissue to be removed or otherwise treated.In diagnostic mode, no resector or other tool is present in the workingchannel, however distention fluid is driven into the uterus tofacilitate observation and diagnosis. In operative mode, the resector orother tool is present in the working channel and impedes the flow ofdistention fluid through the working channel into the uterus. Theinsertion or removal of the resector or other tool from the workingchannel can cause disruptive or dangerous changes in the distention ofthe uterus.

To avoid this problem, U.S. Pat. Nos. 8,062,214 and 8,419,626 disclosethe use of two valves at the access port of the endoscope that can beused to control the flow impedance of distention fluid into the workingchannel of the endoscope. The first valve can be an on/off valve thatcontrols the flow of distention fluid into the working channel of theendoscope. The second valve can be a two position valve that controlsthe flow impedance into the working channel. When the second valve is ina first position, the access port is open permitting the resector orother tool can be inserted through the working channel. In addition,second valve can be configured whereby it also allows unimpeded flow ofthe distention fluid into the working channel where it is impeded by theresector or other tool in the working channel. When the second valve isin a second position, the access port is closed whereby the resector orother tool cannot be inserted into the working channel. However, in thesecond position, the second valve is configured to allow the distentionfluid to flow through a smaller orifice that approximates the impedanceproduced when the resector or other tool is present in the workingchannel. As a result, the fluid impedance is substantially the sameregardless of whether the resector or other tool is present in theworking channel and the position of the second valve which helps toreduce the risks associated with larger changes in distention fluidpressure.

SUMMARY

To aid in addressing these issues, in an aspect of the presentdisclosure, a surgical system can include a first instrument having afluid flow channel and a second instrument receivable by the firstinstrument fluid flow channel. The second instrument can include anaspiration channel. The system can include a valve coupled to the firstinstrument and configured to control fluid flow through the firstinstrument channel. The valve can be configured such that impedance offluid flow through the first instrument channel can be substantially thesame without the second instrument received in the first instrumentchannel and with the first instrument channel partially blocked by thesecond instrument such that the first instrument channel is limited to aregion between the first and second instruments.

Embodiments of this aspect of the present disclosure may include one ormore of the following features.

Embodiments of the present present disclosure can be directed to device,such as an endoscope, that can be used to control the distention fluidpressure using a single, multi-position valve. The device can include aworking channel extending from a proximal end to a distal end thatincludes an access port at the proximal end. The access port can beadapted to receive a resector or other tool useful for endoscopictreatment of tissue adjacent the distal end of the device. The proximalend can include a fluidic connection enabling the device to be connectedto a source of distention fluid that can be driven into the surgicalsite (e.g., a uterus) to distend the tissue in the area of the surgicalsite. A valve can be placed in the fluid path between the fluidicconnection and the working channel to control the flow of distentionfluid into the working channel.

The valve can have two or more operative positions for controlling theflow of distention fluid into the working channel. In a first position,the valve is open to unrestricted flow of distention fluid into theworking channel. In a second position, the valve directs the flow ofdistention fluid through a flow restricted path into the workingchannel. The flow restricted path can be configured to produce the sameflow impedance as when the resector or other tool is in the workingchannel. A third position can be provided wherein the valve is closedpreventing distention fluid from flowing into the working channel.

In some embodiments, the first instrument can include an outer memberand an inner member. The inner member can include a first instrumentchannel therethrough. The inner member can be received within the outermember, and the outer member and the inner member can define a secondfluid flow channel therebetween. The second instrument can include atube defining a second instrument channel therethrough. The tubepartially blocks the first instrument fluid flow channel when receivedtherein. The second fluid flow channel can have a cross-sectional areaof, e.g., about 0.0083 to about 0.0249 square inches, preferably about0.0166 square inches. The first instrument fluid flow channel can have across-sectional area of, e.g., about 0.0053 to about 0.0159 squareinches, preferably about 0.0106 square inches. The second instrumentchannel can have a cross-sectional area of, e.g., about 0.0042 to about0.013 square inches, preferably about 0.0085 square inches.

In some embodiments, the valve can include a housing and a body withinthe housing. The body defines a flow path therethrough and is moveablerelative to the housing between a first position in which the fluid isdirected to flow through a first flow path to the first instrumentchannel and a second position in which the fluid is directed to flowthrough a second flow path to the first instrument channel. In the firstposition, the tube of the second instrument tube partially blocks thefirst instrument fluid flow channel when received therein causing thefluid flow through the first instrument fluid flow channel to beimpeded. In the second position, the first instrument fluid flow channelis not impeded by the tube of the second instrument, but the second flowpath can be configured to impede fluid flow to the first instrumentfluid flow channel such that the fluid flow is about that same as whenthe tube of the second instrument tube partially blocks the firstinstrument fluid flow channel. In accordance with some embodiments ofthe present disclosure, the impedance produced by the second flow pathcan be adjustable. In accordance with some embodiments of the presentdisclosure, the impedance produced by the second flow path can bechanged by changing or replacing a structure of the second flow path.

The system can include a pump and the first instrument is configured toconnect to the pump such that the pump infuses fluid through the firstinstrument channel. The pump can be programmed to infuse fluid throughthe first instrument channel to maintain a substantially constantpressure of between about 60 mm Hg and about 120 mm Hg inside adistensible organ. A sensor coupled to the pump can sense a flowimpedance at a given flow rate, and a controller coupled to the sensorand the pump can compare the flow impedance to a predetermined flowimpedance for the given flow rate to verify the identity of the firstand second instruments.

The second instrument channel can be in fluid communication with asource of suction and a regulator can be interposed between the secondinstrument channel and the source of suction to regulate an amount ofsuction applied through the second instrument channel.

According to another aspect of the present disclosure, a method ofregulating inflow through a valve includes positioning the valve in afirst position directing the inflow along a path having a firstimpedance of flow into a working channel and positioning the valve in asecond position directing the inflow along a path having a secondimpedance of flow into the working channel; and introducing a surgicalinstrument inserting the surgical instrument into the working channel.When the valve is in the first position and the surgical instrument isinserted into the working channel the impedance of flow into the workingchannel is about the same as the impedance of flow into the workingchannel when the valve is in the second position and the surgicalinstrument is removed from the working channel.

According to another aspect of the present disclosure, an apparatus forsurgery can include an outer member and an inner member received withinthe outer member. The outer member and the inner member can define afirst channel therebetween. The inner member can include an optical lensand can define a second channel for receiving a surgical instrument. Thefirst and second channels can be configured such that a pump having aninflow rate of up to about 0.7 L/min connected to the second channel canmaintain fluid pressure inside an organ.

Embodiments of this aspect can include one or more of the followingfeatures. A pump can be coupled to the second channel to introduce fluidthrough the second channel at an inflow rate up to about 0.7 L/min. Theouter member can include a plurality of holes in fluid communicationwith the first channel. The plurality of holes can be positioned in adistal portion of the outer member. The second channel can include aD-shaped cross-section. The first channel can have a cross-sectionalarea, e.g., of about 0.0083 to about 0.0249 square inches, preferablyabout 0.0166 square inches. The second channel can have across-sectional area of, e.g., about 0.0053 to about 0.0159 squareinches, preferably about 0.0106 square inches. The second channel canreceive the surgical instrument therethrough. The surgical instrumentcan include a suction channel with a cross-sectional area of, e.g.,about 0.0042 to about 0.013 square inches, preferably about 0.0085square inches. A valve can be coupled to the inner member for regulatinginflow through one of two or more pathways to the second channel suchthat inflow through a first pathway when the surgical instrument isreceived in the second channel has an impedance equal to the impedancethrough the second pathway when the surgical instrument is removed fromthe second channel.

According to another aspect of the present disclosure, a method includesinfusing fluid into a distensible organ, and maintaining a substantiallyconstant fluid pressure inside the distensible organ between about 60 mmHg and about 120 mm Hg.

According to another aspect of the present disclosure, a system caninclude an endoscope defining a channel therethrough and a surgicalinstrument received within the endoscope channel. The surgicalinstrument can include a channel therein for connection with a source ofsuction. A regulator can be coupled to the surgical instrument channelbetween the instrument channel and the source of suction to regulate anamount of suction applied through the instrument channel.

Additional aspects of the present disclosure will be apparent to thoseof ordinary skill in the art in view of the detailed description ofvarious implementations, which is made with reference to the drawings, abrief description of which is provided below.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 shows a schematic diagram of a resection system according to someembodiments of the present disclosure.

FIG. 2A shows an exploded, perspective view of a hysteroscope of thesystem of FIG. 1 .

FIG. 2B shows a perspective view of the assembled hysteroscope of FIG.2A.

FIG. 3A shows a longitudinal cross-sectional view of the hysteroscope ofFIG. 2B.

FIG. 3B shows a cross-sectional view of the hysteroscope of FIG. 2Btaken along line 3B-3B.

FIG. 4 shows a perspective view of the hysteroscope of FIG. 2B with aresector received therethrough.

FIG. 5 shows a cross-sectional view of the hysteroscope and resector ofFIG. 4 taken along line 5-5.

FIG. 6 shows a diagrammatic view of a valve in a first positionaccording to some embodiments of the present disclosure.

FIG. 7 shows a diagrammatic view of a valve in a second positionaccording to some embodiments of the present disclosure.

FIG. 8 shows a diagrammatic view of a valve in a third positionaccording to some embodiments of the present disclosure.

FIG. 9 shows a schematic diagram of a fluid management system of theresection system of FIG. 1 .

FIG. 10 shows a perspective view of an obturator for use with a sheathof the hysteroscope of FIG. 2A.

FIGS. 11-13 show the obturator, hysteroscope and resector in use.

FIG. 14 shows a graph showing the impedance through the hysteroscope atvarious flow rates.

DETAILED DESCRIPTION

The present disclosure is directed to a method and a system forendoscopically resecting tissue in a distended organ. The system caninclude a valve that enables the impedance to the inflow of distentionfluid through the system into the distended organ to be maintainedsubstantially the same, even as surgical instruments are inserted andremoved from the endoscope during the surgical procedure. Maintaining aneven distention pressure can be beneficial to the patient in that it canhelp to reduce the risks of over distention and intravasation and helpto keep the surgical procedure as short as possible.

Referring to FIG. 1 , the illustrative embodiment of the tissueresecting system 10 according to some embodiments of the presentdisclosure includes an endoscope, e.g., hysteroscope 100, having adistal portion 102 insertable into a distensible organ, e.g., a uterus,of a patient 20 to flow fluid into and remove fluid from the organ. Thehysteroscope 100 can be connectable to fluid bags 17 (mounted on a cart15 by an inflow line 30 to deliver fluid to the hysteroscope 100. Inaccordance with some embodiments, the inflow line 30 runs through apump, e.g., peristaltic pump 310, of a fluid management control unit 300on cart 15. The fluid management control unit 300 and/or the Pump 310control the pressure of the fluid delivered along inflow line 30 tohysteroscope 100. System 10 can also be connectable to a gravitycontainer 40 on cart 15 connected by an outflow line 32 to an outflowport 105 on hysteroscope 100 to collect the outflow of fluid fromhysteroscope 100, under the force of gravity. In accordance with someembodiments, the outflow line 32 is optionally connected to a surgicaldrape 22 to collect fluid from patient 20 in gravity container 40.

As shown in the illustrative embodiment, system 10 includes a resector200 that can be received within hysteroscope 100 during use to resecttissue from the organ. The resector 200 in this embodiment includes ahandle 205 and a distal portion 210 that extends out of distal portion102 of hysteroscope 100. Distal portion 210 includes a working end 220,e.g., a morcellator that can be actuated to cut tissue from the organ.In this embodiment, handle 205 includes a motor (not shown) coupled toworking end 220 to rotate working end 220 about a longitudinal axis tocut tissue. Also, optionally located on cart 15 is a resector controlunit 60 of system 10 connected by a wire 64 to resector 200 to controlmovement of working end 220. In this embodiment, system 10 includes afoot-pedal 62 connected to control unit 60 by a wire 64 to actuatecontrol unit 60.

Also, optionally located on cart 15 is one or more vacuum containers 42of system 10 connected by suction line 34 to a suction port 230 onresector 200 to collect fluid and tissue suctioned through resector 200.In this embodiment, at least one of vacuum containers 42 includes atissue trap 43 that collects tissue suctioned through suction lines 34for later examination, e.g., by a pathologist. In this embodiment,system 10 also includes a vacuum regulator 400 connected by a suctionline 36 to vacuum containers 42 and by vacuum line 38 to a vacuum source(not shown) to regulate suction provided by the vacuum source throughsuction channel 204 of resector 200.

Also, optionally located on cart 15 is a fluid monitoring unit 18 ofsystem 10 that tracks the amount of fluid collected in gravity container40 and vacuum containers 42 and the amount of fluid pumped by fluidmanagement control unit 300 and can be configured to set off an audibleand/or visual alarm if the difference between the amounts of fluidpumped and collected is above a threshold value, thus minimizing thepossibility of excess fluid intravasation.

In this embodiment, part of system 10 includes a visualizing and imagingassembly 50 that includes a camera 51 coupled to a camera port 106 ofhysteroscope 100, and a light source 52 coupled by a fiber optic cable54 to a light port 109 of hysteroscope 100. Together, camera 50 andlight source 52 allow a user to remotely visualize the tissue at distalend 102 of hysteroscope 100. In this embodiment, assembly 50 alsoincludes an imaging station 70 connected by a fiber optic cable 56 tocamera 50. Imaging station 70 includes one or more monitors 72 forviewing images from camera 50 and a capture system 74 for making arecording of the images.

Referring to FIGS. 2A and 2B, hysteroscope 100 optionally includes asheath 80 that has a tube 120 with an inner wall 122 defining a channel121 therethrough. In this embodiment, distal end 102 of tube 120includes a plurality of holes 112 in communication with channel 121 forallowing fluid to flow out of an organ through channel 121. In thisembodiment, sheath 80 has a proximal portion 84 that includes outflowport 105. In this embodiment, outflow port 105 is in fluid communicationwith channel 121. An on/off valve 123 is optionally positioned betweenoutflow port 105 and channel 121 for turning on and off fluid flow fromchannel 121 to outflow port 105.

In this embodiment, hysteroscope 100 includes a scope housing 90 thathas an elongated member 124 removably receivable in tube 120. Member 124includes an outer wall 126 and an inner wall 125. In this embodiment,inner wall 125 defines an inflow channel 130. A proximal portion 94 ofscope housing 90 includes inflow port 110, and a valve 150 which arefluidly connected to inflow channel 130, as described below. Member 124also defines a lens channel 140 that houses an optical lens 142. Scopehousing 90 includes a proximal portion 94 that includes camera port 106and light port 109, which are coupled to optical lens 142 by fiber opticlines (not shown). Light travels from light port 109 to distal end 102of hysteroscope 100 to illuminate objects near distal end 102. Light forimages of those objects are received by optical lens 142, and travelthrough camera port 106 to camera (FIG. 1 ), to allow the user to viewthe organ through hysteroscope 100. This configuration enables lenschannel 140 to be positioned adjacent to inflow channel 130 to help keepoptical lens 142 clear of debris during use. Proximal portion 94 ofscope housing 90 optionally includes a pin 92 receivable in a J-shapedslot (not shown) in sheath 80 to releasably lock scope housing 90 tosheath 80 when member 124 is received in tube 120.

Referring also to FIGS. 3A and 3B, when member 124 is received in tube120, inner wall 122 of tube 120 and outer wall 126 of member 124 definea passive outflow channel 128 therebetween. Passive outflow channel 128can be divided into a left portion 128A and a right portion 128B, whichreconnect at outflow port 105. In this embodiment, passive outflowchannel 128 is in fluid communication with holes 112 in distal end 102of tube 120 and with outflow port 105 to permit passive outflow of fluidfrom the organ under the force of gravity. It will be understood thatoutflow channel 128 need not be divided. Inner wall 125 of member 124defines inflow channel 130 in fluid communication with an aperture 108in distal end 102 of hysteroscope 100 to permit fluid flow into theorgan. Fluid can flow through passive outflow channel 128 along a paththat is completely separate from a path along which fluid flows throughinflow channel 130.

Referring to FIG. 3B, inflow channel 130 and passive outflow channel 128can be sized and configured so that fluid management control unit 300,which has an inflow rate of up to 0.7 L/min, is able to maintain asubstantially constant fluid pressure inside a distensible organ bypumping sufficient fluid into the organ through inflow channel 130 tobalance fluid flow out of the organ through passive outflow channel 128,as described below. For example, inflow channel 130 can be configured tohave a D-shaped cross-section with a cross-sectional area, e.g., ofabout 0.0153 to about 0.0461 square inches, preferably about 0.0307square inches, and each portion 128A, 128B of passive outflow channel128 can have a crescent-shaped cross-section with a combinedcross-sectional area, e.g., of about 0.0083 to about 0.0249 squareinches, preferably about 0.0166 square inches. It should be understoodthat other configurations and sizes of inflow channel 130 and passiveoutflow channel 128 can be used, so long as outflow of fluid throughoutflow channel 128 does not exceed the ability of fluid managementcontrol unit 300 to pump fluid into the organ through inflow channel 130at least at the same flow rate as the outflow of fluid.

Referring to FIGS. 4 and 5 , in this embodiment, resector 200 includes astationary elongated outer tube 202 and a rotatable inner tube 201 thatis coupled to working end 220 (not shown). Inflow channel 130 receivesresector 200 therethrough. In this embodiment, the cross-section ofinflow channel 130 is selected such that inflow channel 130 can be onlypartially blocked by resector 200, allowing fluid to continue to flowinto the organ through a region of inflow channel 130 unblocked byresector 200, located between inner wall 125 and elongated tube 202. Inthis embodiment, inner tube 201 of resector 200 defines a suctionchannel 204 having an opening 206 at working end 220 of resector 200 andin fluid communication with suction port 230 of resector handle 205(FIG. 1 ) to permit suction of fluid and tissue from the organ. Fluid isdrawn through suction channel 204 along a path that is completelyseparate from the paths along which fluid flows through outflow channel128 and inflow channel 130.

Referring to FIG. 5 , passive outflow channel 128, inflow channel 130,and suction channel 204 can be sized and configured so that fluidmanagement control unit 300 maintains the substantially constant fluidpressure inside the organ by pumping sufficient fluid into the organ tobalance fluid flow out of the organ through passive outflow channel 128and suction of fluid out of the organ through suction channel 204, asdescribed below. For example, in this embodiment, the portion of inflowchannel 130 not blocked by resector 200 has a cross-sectional area ofabout 0.0106 square inches, passive outflow channel 128 has across-sectional area of about 0.0166 square inches, and suction channel204 has a cross-sectional area of about 0.0085 square inches. It shouldbe understood that other configurations and sizes of inflow channel 130,passive outflow channel 128, and suction channel 204 can be used, solong as outflow of fluid through outflow channel 128 and suction offluid through suction channel 204 do not exceed the ability of fluidmanagement control unit 300 to pump fluid into the organ through inflowchannel 130 at the same flow rate as the outflow of fluid.

The ability of fluid management control unit 300 to maintain asubstantially constant fluid pressure in the organ can be furtherfacilitated by valve 150 of scope housing 90, which maintainssubstantially the same fluid flow impedance through inflow channel 130regardless of whether resector 200 is positioned in scope housing 90.For example, FIG. 14 shows the impedance through hysteroscope 100 atvarious flow rates, regardless of whether resector 200 is positioned inscope housing 90. By maintaining a substantially constant fluid flowimpedance, valve 150 facilitates fluid management control unitmaintaining a substantially constant pressure in the organ regardless ofwhether resector 200 is positioned in scope housing 90. Impedance refersto the pressure drop in fluid between two points (in this case betweeninflow port 110 and the distal end of inflow channel 130) and variesproportional to the square of the flow rate.

FIGS. 6-8 show diagrammatic views of valve 150 located at the proximalend of the housing of the hysteroscope 100. In this embodiment, thevalve 150 includes an inlet port 110 enabling the hysteroscope 100 to beconnected to a source of fluid (not shown). In this embodiment, thevalve 150 includes a valve body 152 that can rotate within the valvehousing 154 to control the flow of fluid into the inflow channel 130. Inthis embodiment, the valve body 152 includes one or more channels 156that connect one or more parts of the hysteroscope 100. In thisembodiment, the valve body 152 includes a valve handle 153 to enable theuser to move the valve body 152 between positions. In the firstposition, the valve body channel 156 connects the inlet port 110 to thechannel 160 such that fluid supplied at the inlet port 110 flows throughchannel 160 into the inflow channel 130. In the second position, thevalve body channel 156 connects the inlet port 110 to the calibrationline 158. The calibration line 158 connects the valve body 154 to thechannel 160 that is connected to the inflow channel 130. The calibrationline 158 can be selected to have a predefined impedance to fluid flowthat is substantially the same as the impedance to fluid flow when thevalve body 152 is in the first position and the resector 200 ispositioned in the inflow channel 130. In this embodiment, the impedanceof the calibration line 158 is determined by the diameter of a portionof the calibration line or a flow restricting mechanism can be part ofthe calibration line 158. In accordance with some embodiments, theimpedance of the calibration line 158 is, optionally, adjusted byadjusting the flow restricting mechanism or by replacing at least aportion of the calibration line 158 with a portion having a larger orsmaller diameter. As shown in FIGS. 6-8 , the inflow channel 130 extendsproximally from the proximal portion 94 of the hysteroscope 100 andinclude an access port 162 into which the resector 200 can be inserted.In accordance with some embodiments, the access port 162 is optionallyfitted with a seal 164 which allows the resector 200 to be inserted andremoved and minimizes leakage of fluid through the access port 162. Theseal 164 can be formed of an expandable material (e.g., rubber,silicone, PDMS) that can expand when the resector 200 is inserted in tothe inflow channel 130, and contracts and remains closed after theresector 200 is removed. In accordance with some embodiments of thepresent disclosure, the access port 162 optionally includes a valve (notshown) that closes the proximal end of the inflow channel 130 whenresector 200 is not present.

FIG. 6 shows a diagrammatic view of a valve 150 in a first positionaccording to some embodiments of the present disclosure. In accordancewith some embodiments of the present disclosure, the valve 150 in thefirst position is configured to allow the maximum fluid flow into thefluid flow channel. In the first position, the inlet port 110 isconnected to channel 160 which directs fluid flow into the inlet channel130. In this embodiment, the valve 150 provides the maximum flow andminimum impedance to fluid flow through the inlet channel 130.

FIG. 7 shows a diagrammatic view of a valve 150 in a second positionaccording to some embodiments of the present disclosure. In accordancewith some embodiments of the present disclosure, the valve 150 in thesecond position is configured to provide impeded fluid flow, at aboutthe same impedance as when the resector 200 is inserted into the inflowflow channel 130. In the second position, the inlet port 110 isconnected to calibration line 158 which directs fluid flow through thecalibration line 158 and into the inlet channel 130. In this embodiment,the valve 150 provides calibrated fluid flow that matches the impedanceto fluid flow when the resector 200 is received in the inflow channel130. In operation, the user can place the valve 150 into the secondposition prior to inserting or removing the resector 200 to prevent aspike of excess fluid and pressure into the uterus during surgery. Thisreduces the risk of harm to the patient from intravasation.

FIG. 8 shows a diagrammatic view of a valve in a third positionaccording to some embodiments of the present disclosure. In accordancewith some embodiments of the present disclosure, the valve 150 in thethird position can be configured to block fluid flow into channel 160and the inflow channel 130 (e.g., this can be the “off” position). Inthe third position, the inlet port 110, calibration line 158 and channel160 can each be closed by the valve body 152 such that no fluid can flowin the inlet port 110 or out via channel 160 or the calibration line158.

In some embodiments of the present disclosure, fluid management controlunit 300 is used to maintain substantially constant fluid pressureinside the organ by pumping sufficient fluid into the organ throughinflow channel 130 to balance fluid flow out of the organ throughpassive outflow channel 128 and from suction of fluid through suctionchannel 204 (when resector 200 is received in hysteroscope 100).Referring to FIG. 9 , fluid management control unit 300 optionallyincludes a peristaltic pump 310 through which runs fluid line 30 thattransmits fluid from fluid bag 17 to inflow port 110 of hysteroscope100. Pump 310 pumps fluid along fluid line 30, controlling the pressureand flow rate of fluid transmitted to hysteroscope 100.

Fluid management control unit 300 optionally also includes a flow ratesensor 315, such as a roller head, a turbine, or an ultrasonic sensor,that measures the flow rate of fluid outputted by pump 310. Control unit300 optionally also includes a pressure sensor, e.g., pressuretransducer 320 that senses the fluid pressure in fluid line 30 after thefluid passes through pump 310. In this embodiment, fluid managementcontrol unit 300 includes an input 345 where a user can input a desiredpressure to be maintained inside the organ, and a memory 340 thatcontains information on the impedance (i.e., pressure drop) through thehysteroscope 100 and resector 200 combination at a range of differentflow rates.

Coupled to pressure sensor 320, pump 310, flow rate sensor 315, input345, and memory 340, is a controller 330, e.g., a microprocessor, thatcontrols the pressure and the flow rate outputted by pump 310 based onthe flow rate measured by flow rate sensor 315, the pressure measured bypressure sensor 320, the information stored in memory 340, and thetarget pressure 345. Based on a measured flow rate and a measuredpressure, controller 330 determines the actual pressure in the organaccording to the information stored in memory 340 that accounts for theimpedance (i.e., pressure drop) through the hysteroscope 100 at variousflow rates. Controller 330 then compares the pressure in the organ withthe target pressure and adjusts the pressure and flow rate outputted bypump 310 accordingly. If the target pressure is greater than the actualpressure, then controller 330 increases the output of pump 310. If thetarget pressure is less than the actual pressure, then controller 330decreases the output of pump 310.

The size and configuration of inflow channel 130, passive outflowchannel 128, and suction channel 204 facilitate controller 330maintaining substantially constant pressure in the organ. In addition,valve 150 facilitates maintaining a substantially constant pressure inthe organ by keeping the impedance through hysteroscope 100 the sameregardless of whether resector 200 is received in hysteroscope 100.Thus, it is not necessary for controller 330 to “know” whether resector200 is positioned in hysteroscope 100. Fluid management control unit 300is able to maintain a relatively constant pressure of fluid within theorgan, e.g., at a preset pressure between about 60 mm Hg and about 120mm Hg.

Fluid management control unit 300 can also include a feature thatverifies that a correct combination of hysteroscope 100 and resector 200is being used (i.e., to ensure that the system is only used when aresector and a hysteroscope having properly balanced flow channels areattached to fluid management control unit 300). Memory 340 contains flowrate and impedance information for each valid combination of ahysteroscope and a resector. Controller 330 is programmed to determinewhether the pressure measured by pressure transducer 320 is within athreshold value of a predetermined pressure for a given flow rate inorder to verify the identity of the combination of the hysteroscope andthe resector. Controller 330 is coupled to a shut-off circuit 360 todisable pump 310 when controller 330 determines that the combination ofhysteroscope and resector is invalid (e.g., when an incorrect sizeresector is used with the hysteroscope). If the combination is verified,then controller 330 overrides shut-off circuit 360 and allows pump 310to pump fluid to hysteroscope 100, as described above. On the otherhand, if controller 330 determines that the combination of thehysteroscope and the resector is invalid (e.g., wrong size resector),the controller 330 activates shut-off circuit 360 to disable pump 310.Controller 330 also is coupled to an alarm 350, e.g., a visual oraudible alarm that is activated when pump 310 is disabled. Controller330 is programmed to make pressure comparisons at several (e.g., threeor four) flow rates prior to use of hysteroscope 100 and resector 200.

In use, a user can assemble the components of the resection system 10 asshown in FIG. 1 . As shown in FIGS. 6 and 7 , the user can positionvalve 150 to the first position. The user can insert the resector 200through hysteroscope 100. The user can verify the combination ofhysteroscope 100 and resector 200 by activating fluid management controlunit 300, as described above with respect to FIG. 9 , to infuse fluidthrough hysteroscope 100 and resector 200 assembly at three or fourdifferent flow rates, to sense the flow impedance through the assembly,and to compare each sensed flow impedance to predetermined flowimpedances. If the combination is verified, the user removes resector200 from hysteroscope 100, and moves valve 150 to the second position,as shown in FIG. 7 .

Referring to FIG. 10 , to position sheath 80 within the uterus, system10 includes an obturator 800 insertable through sheath 80 when scopehousing 90 is removed from sheath 80. Obturator 800 includes a shaft810, a sharp, distal tip 820, and a proximal handle 840. Disposedbetween handle 840 and shaft 810 is a pin 830 that fits into theJ-shaped slot (not shown) in sheath 80 to removably lock obturator 800to sheath 80.

Referring to FIG. 11 , with obturator 800 received within sheath 80 suchthat tip 820 extends beyond distal portion 102 of sheath 80, the userinserts obturator 800 and sheath 80 into a uterus 900. Referring to FIG.12 , the user removes obturator 800 from sheath 80, and inserts scopehousing 90 through sheath 80 and into uterus 900. The user then movesvalve 150 to the second position, as shown in FIG. 7 , and activatesfluid management control system 300 to pump fluid through channel 130 ofhysteroscope 100 and into uterus 900 along flow path B, at a firstimpedance, to distend uterus 900, as shown in FIG. 12 . At the sametime, the user allows fluid to flow out of uterus 900 via holes 112 andchannel 122 in hysteroscope 100 along flow path C to gravity container40, in order to keep the pressure inside uterus 900 between about 60 mmHg and 120 mm Hg.

Once uterus 900 has been distended, with valve 150 in the secondposition, as shown in FIG. 7 , the user inserts resector 200 through theaccess port 162 and inflow channel 130 of hysteroscope 100, and intouterus 900, as shown in FIG. 13 and positions valve 150 to the firstposition, as shown in FIG. 6 . Fluid management control system 300continues to pump fluid so that fluid flows through inflow channel 130,between inner wall 125 and resector 200 and into uterus 900 at a secondimpedance substantially equal to the first impedance. At the same time,the user allows fluid to flow out of uterus 900 via holes 112 andchannel 128 in hysteroscope along flow path C and suctions fluid out ofuterus 900 through resector 200 along flow path D, in order to keep thepressure inside uterus 900 between about 60 mm Hg and 120 mm Hg. Fluidsuctioned along path D is collected in vacuum containers 42. The useralso can actuate vacuum regulator 400 to control the amount of suctionthrough resector 200 along path D. Preferably, the user maintains thevacuum pressure above approximately 100 mm Hg (to facilitate tissueremoval) and below approximately 200 mm Hg (to inhibit uterus collapse).In order to inhibit uterus collapse, vacuum regulator 400 is preset tonot allow vacuum pressure greater than a threshold value, e.g., 200 mmHg, to be applied.

The user visualizes the inside of uterus 900 on monitors 72 ofvisualizing and imaging assembly 50. The user actuates foot pedal 62,which activates resector control unit 60. Resector control unit 60activates resector 200, e.g., by rotating a cutting blade 910 at workingend 220 of resector 200, to cut tissue from uterus 900. Fluid and tissuecut by blade 910 are suctioned through channel 204 of resector 200 alongpath D. During the procedure, resector 200 can be removed fromhysteroscope 100 while hysteroscope 100 remains inside uterus 900, e.g.,to clean resector 200 or change instruments, so long as the user movesvalve 150 to the second position, as shown in FIG. 7 , while removingresector 200 to limit the inflow of fluid through channel 130 ofhysteroscope 100.

During the procedure, fluid monitor unit 18 can track the amount offluid infused through resector 200 and the amount of fluid collected ingravity container 40 and vacuum containers 42. Fluid monitor unit 18 canset off an audible or a visual alarm if substantially more fluid isinfused than collected, which indicates that the patient is absorbingtoo much fluid. Once the procedure is complete, the user can close valve150 by moving it to the third position, as shown in FIG. 8 , andremoving resector 200 and hysteroscope 100 from uterus 900.

A number of embodiments of the present disclosure have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the presentdisclosure. For example, the shape, size, and configuration of the fluidflow channels through the hysteroscope and the resector could bedifferent than that shown and described, such as having an inflowchannel with an elliptical, square, triangular, or trapezoidalcross-section. Instead of a blind bore, the body of the secondary valvecould include a peripheral channel formed in an outer surface of thebody. Instead of a secondary valve, the primary valve could beelectronically controlled to maintain a constant impedance through thehysteroscope regardless of whether the resector is inserted through thehysteroscope. The hysteroscope can be used with other types of resectortools having rotatable working ends, such as burrs or drills. Thehysteroscope also can be used with a resector tool having areciprocating working end, such as the instrument disclosed in U.S. Pat.No. 7,510,563 entitled “Reciprocating rotary arthroscopic surgicalinstrument,” the entirety of which is incorporated herein by reference.The fluid management system can include another type of pump, such as acentrifugal, piston, or diaphragm pump. The vacuum regulator couldinclude a manually or electronically operable valve, a flow sensor,and/or a pressure gauge. The devices shown can be used for surgery onother distensible organs, such as a shoulder or knee joint. Differentcombinations of the components of the system could be used or componentscould be added or deleted. These and other embodiments are within thescope of the following claims.

Other embodiments are within the scope and spirit of the presentdisclosure. For example, due to the nature of software, functionsdescribed above can be implemented using software, hardware, firmware,hardwiring, or combinations of any of these. Features implementingfunctions may also be physically located at various positions, includingbeing distributed such that portions of functions are implemented atdifferent physical locations.

Each of the above concepts and obvious variations thereof iscontemplated as falling within the spirit and scope of the claimedinvention, which is set forth in the following claims.

What is claimed is:
 1. A hysteroscope comprising: an access portdefining a fluid flow channel and configured to receive an instrumentthrough the fluid flow channel; a valve inlet configured to receive afluid; a valve housing operably coupled to the valve inlet; a valve bodydefining a body channel, the valve body movable within the valve housingat least between a first open position and a second open position; and avalve channel in fluid communication with the fluid flow channel of theaccess port; wherein when the valve body is: in the first open position,a first flow path provides a first impedance to fluid flow from thevalve inlet through the body channel of the valve body and through afirst opening in the valve housing to the fluid flow channel of theaccess port; and in the second open position, a second flow pathprovides a second impedance to fluid flow from the valve inlet throughthe body channel of the valve body, through a second opening in thevalve housing and through a calibration line to the fluid flow channelof the access port, wherein fluid is prevented from flowing through thecalibration line when the valve is in the first open position.
 2. Thehysteroscope according to claim 1, wherein a third impedance to flow isproduced when an instrument is received within the fluid flow channel ofthe access port, wherein the third impedance is substantially the sameas the second impedance when an instrument is not received within thefluid flow channel of the access port and the valve body is in thesecond open position.
 3. The hysteroscope according to claim 1, whereinthe valve body has a closed position wherein fluid flow is blocked frompassing through the valve housing when the valve body is in the closedposition.
 4. The hysteroscope according to claim 1, further comprising aseal operably coupled to a proximal portion of the access port, the sealconfigured to reduce fluid flow out of the access port.
 5. Thehysteroscope according to claim 1, wherein a distal portion of theaccess port is disposed on a proximal portion of the hysteroscope. 6.The hysteroscope according to claim 1, further comprising thecalibration line, wherein the calibration line defines a calibrationchannel in fluid communication with the second opening in the valvehousing and the fluid flow channel of the access port.
 7. Thehysteroscope according to claim 1, wherein the valve inlet is configuredto operably couple to a pump such that the pump causes fluid to flowthrough the fluid flow channel of the access port.
 8. A surgical systemcomprising: a hysteroscope including an access port operably coupled tothe hysteroscope, the access port defining a fluid flow channelconfigured to receive an instrument through the fluid flow channel; anda valve operably coupled to the hysteroscope, the valve including: avalve inlet configured to receive a fluid; a valve housing operablycoupled to the valve inlet; a valve body defining a body channel, thevalve body movable within the valve housing at least between a firstopen position and a second open position; and a valve channel in fluidcommunication with the fluid flow channel of the access port; whereinwhen the valve body is: in the first open position, a first flow pathprovides a first impedance to fluid flow from the valve inlet throughthe body channel of the valve body and through a first opening in thevalve housing to the fluid flow channel of the access port; and in thesecond open position, a second flow path provides a second impedance tofluid flow from the valve inlet through the body channel of the valvebody, through a second opening in the valve housing and through acalibration line to the fluid flow channel of the access port, whereinfluid is prevented from flowing through the calibration line when thevalve is in the first open position.
 9. The surgical system according toclaim 8, wherein a third impedance to flow is produced when aninstrument is received within the fluid flow channel of the access port,wherein the third impedance is substantially the same as the secondimpedance when an instrument is not received within the fluid flowchannel of the access port and the valve body is in the second openposition.
 10. The surgical system according to claim 8, wherein thevalve body has a closed position wherein fluid flow is blocked frompassing through the valve housing when the valve body is in the closedposition.
 11. The surgical system according to claim 8, furthercomprising a seal operably coupled to a proximal portion of the accessport, the seal configured to reduce fluid flow out of the access port.12. The surgical system according to claim 8, wherein a distal portionof the access port is operably coupled to a proximal portion of thehysteroscope.
 13. The surgical system according to claim 8, wherein thevalve includes the calibration line and the calibration line defines acalibration channel in fluid communication with the second opening inthe valve housing and the fluid flow channel of the access port.
 14. Thesurgical system according to claim 8, further comprising a pump coupledto the valve inlet such that the pump causes fluid to flow through thefluid flow channel of the access port.
 15. The surgical system accordingto claim 14, wherein the pump is programmed to cause fluid to flowthrough the fluid flow channel of the access port to maintain asubstantially constant pressure of between about 60 mm Hg and about 120mm Hg inside a distensible organ.
 16. The surgical system according toclaim 14, further comprising a sensor coupled to the pump to sense aflow impedance at a given flow rate and a controller coupled to thesensor and the pump to compare the flow impedance to a predeterminedflow impedance for the given flow rate.
 17. The surgical systemaccording to claim 16, wherein the sensor is configured to identify aninstrument positioned through the access port based on the sensed flowimpedance.